Succinic acid oximidophosphoric esters

ABSTRACT

New and valuable substituted succinic acid oximidophosphoric esters having a strong insecticidal action, pesticides containing these compounds as active ingredients, a process for controlling pests with these compounds, and a process for their production.

The present invention relates to new and valuable substituted succinic acid oximidophosphoric esters having a strong insecticidal action, pesticides containing these compounds as active ingredients, and a process for their production.

It is known (German 962,608) to use O,O-diethylsuccinic oximidothiophosphate for combatting insects. However, its action is poor.

We have now found that substituted succinic acid oximidophosphoric esters of the general formula ##EQU1## where X denotes sulfur or oxygen, R¹ denotes lower alkyl (methyl, ethyl, propyl), R² denotes lower alkoxy (methoxy, ethoxy), lower alkyl (methyl, ethyl), or aryl (phenyl), R³ denotes alkyl (C₁ to C₁₀), cycloalkyl, alkenyl, cycloalkenyl, aryl (phenyl), or benzyl, R⁴, R⁵ and R⁶ may be identical or different and each denotes hydrogen, lower alkyl (C₁ to C₄), or phenyl, or R³ and R⁴ together denote a hydrocarbon ring having several (five or six) members, have an excellent insecticidal action.

The new active ingredients may be prepared by reacting a phosphorylation agent of the formula ##EQU2## R¹, R² and X having the above meanings and hal denoting halogen (chloro, bromo), with a substituted succinic acid oximide of the formula ##EQU3## where R³, R⁴, R⁵ and R⁶ have the above meanings, in the form of its alkali metal salt or in the presence of an acid-binding agent.

The substituted succinic acid oximides, and their sodium salts, may be prepared by reaction of substituted succinic acid diesters with hydroxylamine alone, or if desired with the addition of suitable substances, e.g., sodium methylate, in accordance with the following scheme: ##EQU4## R³, R⁴, R⁵ and R⁶ having the above meanings, and R denoting lower alkyl. The substituted succinic acid oximides may be separated out by adding acid to the sodium salts. It is also possible to use appropriately substituted succinic anhydrides as starting materials, the procedure then being analogous to that described by G. Zinner in Arch. Pharm., 301, 776, 1968.

The substituted succinic acid diesters, succinic anhydrides and succinic acids required for the synthesis of the substituted succinic acid oximides are described in the literature.

The active ingredients are advantageously prepared in the presence of acid-binding agents. Suitable such agents are alkali metal carbonates, alcoholates and hydroxides, and organic bases, e.g., pyridine and trialkylamines. It is also possible to react the alkali metal salts of the abovementioned substituted succinic acid oximides with the abovementioned phosphoric halides. The reaction is advantageously carried out in an inert organic solvent at from 0° to 150°C, preferably 30° to 130°C. Particularly suitable solvents are ketones, benzene, toluene, xylene, dioxane, nitriles such as acetonitrile and propionitrile, dimethylformamide, dimethyl sulfoxide and esters of organic acids.

The phosphorylation components needed as starting materials are prior art.

The new phosphoric esters are either crystalline, or colorless to reddish oils which are sparingly soluble in water and are extremely difficult to distil, even at considerable subatmospheric pressure, without decomposition occuring. The compounds have an excellent action on a multiplicity of animal crop plant pests without damaging the plants themselves.

The new phosphoric esters are suitable for combatting for instance the following pests: in fruit:

Capua reticulana

Carpocapsa pomonella

Cheimatobia brumata

Psylla piri

Lyonetia clerkella

Nepticula malella

Adoxophyes orana

Rhagoletis cerasi

Aphis pomi

Hoplocampa brevis

in Indian corn:

Sesamia cretica

Chilo zonellus

Diatraea saccharalis

Prodenia ornitogalli

Laphygma frugiperda

in rice:

Nezara viridula

Chilo spec.

in groundnuts:

Aphis craccivora

in sugar cane:

Odontotermes obesus

in grapes:

Polychrosis botrana

Sparganothis pilleriana

in beet:

Aphis fabae

Pegomya hyoscyami

Cassida nobilis

Agrotis segetum

Piesma quadratum

in cotton:

Heliothis zea

Heliothis armigera

Pectinophora gossypiella

Dysdercus spec.

Due to their excellent insecticidal properties the abovementioned products are most suitable for use as pesticides in the plant protection sector.

The insecticidal action may be broadened considerably by adding other insecticides, and adapted to existing conditions.

The preparation and use of the new compounds are illustrated by the following examples.

EXAMPLE 1 Solution of hydroxylamine in CH₃ OH

69 parts by weight of hydroxylamine hydrochloride is mixed with 100 parts of CH₃ OH. While stirring and under nitrogen, 180 parts by weight of a 30 wt% technical grade solution of NaOCH₃ /CH₃ OH is dripped in with external cooling. The mixture is finally stirred for 1 hour at 30°C. The sodium chloride is separated.

3,3-dimethylsuccinic acid oximide, sodium salt

174 parts by weight of 2,2-dimethylsuccinic acid dimethyl ester is dissolved in 100 parts of CH₃ OH. The solution of hydroxylamine obtained above is added to this mixture while stirring. 180 parts by weight of a 30 wt% solution of NaOCH₃ /CH₃ OH is subsequently dripped in over a period of 30 minutes. The mixture is then heated for 1 hour under reflux, after which time the reflux condenser is replaced by a short column and a descending condenser, and the methanol is distilled off, the portion which is removed being replaced by xylene (dripped in). The salt soon begins to precipitate colloidally. The internal temperature is finally raised to 135°C, pure xylene distilling off. The suspension of the sodium salt may subsequently be employed for phosphorylation, or the sodium salt is separated. There is obtained 165 parts by weight (100% of theory) of the sodium salt of 3,3-dimethylsuccinic acid oximide.

O,O-diethyl-O-(3,3-dimethylsuccinic acid oximido)-thionophosphate

The suspension of 165 parts by weight of the sodium salt of 3,3-dimethylsuccinic acid oximide in xylene obtained above is heated at 60°C; while stirring thoroughly, 188 parts by weight of diethoxythiophosphoryl chloride is dripped in. The mixture is stirred for 4 hours at this temperature and then allowed to cool. The precipitated sodium chloride is suction filtered, and the solution of the phosphoric ester in xylene is washed first with 200 parts by weight of a 10 wt% aqueous NaHCO₃ solution and then with 200 parts by weight of water, and is then dried over Na₂ SO₄. After evaporation of the solvent a pale yellow oil remains.

    ______________________________________                                         Yield: 245 parts by weight = 83% of theory.                                             C      H       N       P      S                                       ______________________________________                                         Calcd.:    40.7     6.1     4.7   10.5   10.8                                  Found:     41.0     6.7     4.3   10.2   10.6                                  n.sub.D.sup.25 : 1.4812.                                                       ______________________________________                                    

The following compounds were prepared analogously: ##EQU5##

The following compounds were used for the biological experiments: ##EQU6##

EXAMPLE 2 Action on caterpillars of the cabbage moth (Plutella maculipennis)

Cabbage leaves are dipped in aqueous formulations of the active ingredients. After the layers have dried caterpillars in the 4th stage are placed on the leaves. The mortality is determined after 48 hours.

    ______________________________________                                         Active ingredient                                                                           Concentration of the                                                                           Mortality                                                      active ingredient                                                              (in wt%)                                                          ______________________________________                                         5              0.05          95%                                               6              0.02          100%                                              3              0.02          100%                                              1              0.005         90%                                               8              0.01          80%                                               7              0.01          80%                                               I              0.1           20%                                               ______________________________________                                    

EXAMPLE 3 Action on bean aphids (Aphis fabae)

Potted bean plants harboring heavy aphid colonies were treated in a spray chamber with aqueous dispersions of the active ingredients. The mortality was determined after 24 hours.

    ______________________________________                                         Active ingredient                                                                           Concentration of the                                                                           Mortality                                                      active ingredient                                                              (in wt%)                                                          ______________________________________                                         5              0.01          98%                                               6              0.01          95%                                               3              0.02          100%                                              1              0.005         80%                                               20             0.04          80%                                               I              0.1           80%                                                              0.05          30%                                               ______________________________________                                    

EXAMPLE 4 Action on granary weevils (Sitophilus granarius)

The weevils were placed for 4 hours on glass (Petri dishes 10 cm in diameter) treated with the active ingredients. The mortality was determined after 24 hours.

    ______________________________________                                         Active ingredient                                                                           Amount of active                                                                               Mortality                                         no.          ingredient per dish                                               ______________________________________                                         5              0.02 mg       90%                                               6              0.025 mg      90%                                               3              0.01 mg       95%                                               1              0.025 mg      100%                                              I              1 mg          35%                                               ______________________________________                                    

EXAMPLE 5 Culture experiment with Drosophila larvae on a nutrient medium treated with active ingredient

    Active ingredient                                                                          Concentration of active                                                                          Mortality                                        no.         ingredient in medium                                               ______________________________________                                         5           12.5       ppm        100%                                         3           5.0        ppm        100%                                         1           2.5        ppm        100%                                         7           10.0       ppm        100%                                         I           25.0       ppm        100%                                                     12.5       ppm         50%                                         ______________________________________                                    

EXAMPLE 6 Contact action on oriental cockroaches (Blatta orientalis)

The experiment was carried out in 1 liter beakers the inside surfaces of which had been treated with the active ingredients.

The mortality was determined after 48 hours.

    ______________________________________                                         Active ingredient                                                                            Amount of active                                                                               Mortality                                        no.           ingredient                                                       ______________________________________                                         5             0.1 mg/beaker   100%                                             6             0.05 mg/beaker  100%                                             3             0.1 mg/beaker   100%                                             1             0.05 mg/beaker  100%                                             I             0.25 mg/beaker  100%                                                           0.1 mg/beaker    40%                                             ______________________________________                                    

EXAMPLE 7

90 parts by weight of compound 3 is mixed with 10 parts by weight of N-methyl-α-pyrrolidone. A mixture is obtained which is suitable for application in the form of very fine drops.

EXAMPLE 8

20 parts by weight of compound 4 is dissolved in a mixture consisting of 80 parts by weight of xylene, 10 parts by weight of the adduct of 8 to 10 moles of ethylene oxide to 1 mole of oleic acid-N-monoethanolamide, 5 parts by weight of the calcium salt of dodecylbenzenesulfonic acid, and 5 parts by weight of the adduct of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

EXAMPLE 9

20 parts by weight of compound 5 is dissolved in a mixture consisting of 40 parts by weight of cyclohexanone, 30 parts by weight of isobutanol, 20 parts by weight of the adduct of 7 moles of ethylene oxide to 1 mole of isooctylphenol, and 10 parts by weight of the adduct of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

EXAMPLE 10

20 parts by weight of compound 5 is dissolved in a mixture consisting of 25 parts by weight of cyclohexanol, 65 parts by weight of a mineral oil fraction having a boiling point point between 210° and 280°C, and 10 parts by weight of the adduct of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

EXAMPLE 11

20 parts by weight of compound 3 is well mixed with 3 parts by weight of the sodium salt of diisobutylnaphthalene-α-sulfonic acid; 17 parts by weight of the sodium salt of a lignin-sulfonic acid obtained from a sulfite waste liquor, and 60 parts by weight of powdered silica gel, and triturated in a hammer mill. By uniformly distributing the mixture in 20,000 parts by weight of water, a spray liquid is obtained containing 0.1% by weight of the active ingredient.

EXAMPLE 12

3 parts by weight of compound 4 is intimately mixed with 97 parts by weight of particulate kaolin. A dust is obtained containing 3% by weight of the active ingredient.

EXAMPLE 13

30 parts by weight of compound 6 is intimately mixed with a mixture consisting of 92 parts by weight of powdered silica gel and 8 parts by weight of paraffin oil which has been sprayed onto the surface of this silica gel. A formulation of the active ingredient is obtained having good adherence. 

We claim:
 1. A succinic acid oximidophosphoric ester of the formula ##EQU7## where X is sulfur, R¹ is lower alkyl, R² is lower alkoxy or phenyl, R³ is lower alkyl or phenyl, R⁴ is hydrogen or lower alkyl, R⁵ and R⁶ are hydrogen and R³ and R⁴ when taken together form a hydrocarbon ring of five or six members.
 2. The compound of the formula ##EQU8##
 3. The compound of the formula ##EQU9##
 4. The compound of the formula ##EQU10##
 5. The compound of the formula ##EQU11##
 6. The compound of the formula ##EQU12##
 7. The compound of the formula ##SPC1##
 8. The compound of the formula ##SPC2## 